Racal Instruments 9901 Maintenance Manual page 55

REMOVAL
OF COVERS
WARN
IN G:
DAN GEROUS AC VOLTAGES ARE EXPOSED
WHEN
COVERS
ARE
REMOVED WITH
AC
SUPPLY
CONNECTED.
5.1
(1)
Set the
POWER
switch
to
'off, switch
off
the a.c. supply at the
supply
point
and unplug
the
power
lead.
(2)
Remove the rubber plugs (located near
to
the rear end) from both side
panels of the instrument
and
slacken,
by
about two
turns,
the
screws
revealed.
(3)
Grip the rear panel assembly
and ease
it
back
from the
main case
to the
maximum
extent available (about
5 mm).
(4)
The
rear
edge
of either
cover can
now
be
lifted
and
the
cover withdrawn
outwards
and
rearwards.
(5)
To replace the covers reverse the
above
procedure.
TRANSFORMER VOLTAGE
SELECTION
5.2 The
instrument
will
normally be dispatched with
the transformer
primary tapping
set to
the
223-251
V
supply range.
To check
the selection
proceed
as follows.
(1)
Unplug
the
power
cable from the supply
and remove
the top
cover
(see
para .5.1).
(2)
Refer to
the
diagrams on
the
next
page
and:
-
(a)
Note
the
diagram which
corresponds to
the local
a.c. supply
voltage.
(b)
Connect the correct
link(s)
and make
the required
line
lead
connection
(L)
as
indicated
in
the appropriate diagram.
(3)
Verify
that the label
on
the rear
panel indicates correctly the selected
voltage range. Alternative
labels
are
provided with the instrument
for
ranges other than
223V
to
251V.
(4)
Replace the top cover.
9901 Vol
.
2
5-2